Old, hmm, I guess it depends on who is asking. In RL I am 52. I started SL in 2003. I always say that SL keeps me young! I'll never be ashamed of my age, many people don't make it this far. I'd have to say most of my friends are around my age or older. But a few are quite a bit younger. To me it doesn't matter as long as they are good people.
I have a few avatars I have made over the years. Recently I decided to make this one look 'old' as nearly every time i log in someone comments on how old I am lol. So why not make her look old. I have my other avatars that look young and beautiful, that's easy to do. This look was more challenging.
SL is fun, I love meeting people of all ages, and there is always something new to learn!